Below is a link to a recent presentation I made to the local IEEE Ottawa Chapter and the Alliance of IEEE Consultants Network (AICN). I trace the evolution of the air interface of wireless systems from 2G (GSM, CDMA/IS95) through 3G and LTE to LTE-Advanced.
Much of the gain in data rates has been achieved on the back of high modulation schemes, wider channel bandwidth, improved coding techniques (CTC), and spatial multiplexing (MIMO). However, the challenge to increase the peak rate is soon reaching the limits of technology, physics, logistics and commercial realities.
To break through the limits, wireless networks will focus on higher-level (or network-level) techniques specifically related to the planning and architecture of the network. Techniques such as fractional frequency reuse, ICIC, and advanced wireless architectures exemplified by the use of small cells will be key to further improvement in spectral efficiency.
Click here to open the presentation.